Screw driver



Sept. 22, 1931.

P.- L. ROBERTSON SCREW DRIVER Filed Jap. 10. 1929 Per 1,. Foaqs o@ l0 rearrangement.

The principal feature ofthe invention Patented Sept. 22, 1931 UNITED f STATES :PETER I.. ROBERTSON, OF MILTON, ONTARIO, CANADA.

SCREW DRIVERA i Application ined January 10,1929. serial Np) 331,516.

The principal. objects of this invention are to provide a screw driver which may be readily adapted for use withr various sizes or types of screws and which may bealtered `y very quicklyto suit the requirements of the user.

A further Object is to improve the construction of the holder ofthe removablebits to enable their more ready adjustment and consists in the novel arrangement ofa plurality of individual bits to be utilized in various combinations and in the novel construction of the bit holder whereby the bits are readily adjusted or replaced therein- This invention is an improvement in Screwdrivers to be used principally inconjunction with my co-pending invention for j improvements in tool holders, filed in the United States Patent Otiice July 2, 1928 under Serial No. 289,954.

In the accompanying drawings, Figure lp. is a perspective view of my improved screw n '25 driver showing the multiple bit arrangement for use with large slotted screws.

Figure 2 is a perspective view of the bit end of the screw driver showing the arrangement of the bits with a smaller screw.

Figure 3 is a perspective view of the bit end of the screw driver showing an arrangement of the bits for use with a perforated screw, such as a wheel spoke nipple.

Figure 4 is a perspective detail ofthe inner bit holder and bits. l

Figure 5 is an enlarged longitudinal sectional detail through the bit holder showing the bits in position, as shown in Figure 1.

In the accompanying drawings, the screw driver shank l is threaded atl its outerend and the portion 2 projecting beyond the thread 3 is slotted longitudinally through the centre to receive the bit holder 4 which is in the forni of a U-shaped member preferably formed of hardened steel and having the Outer sides 5 of its ends bevelled and the inner sides chamfered at 6.

The holder 4 fits snugly into the slot 7,

its linner end to engagey the thread 3 holds the bit holder' securely in place.

*The sleeve`8 is formed with an inwardly bevelled surface V9 at lis outward end to en-V u gage the bevelled surfaces 5of the bit holder 55 to squeeze them inwardly to bind the bits inposition when placed therein side by side. Y AThe bits 10 are formed of square bars of tool steel eaclifhaving one end reduced to form the narrow screw driverA extremity 11. lt() These are suitably tapered so that vthey will iit a comparatively small screw vbut will be strongV enough to enter the deeper slots of a larger vscrewandto eiectivelylturn it.

.The opposite ends ,of the bits may be i 65 square for use with socket type screws.

. The bits are placed together inthe holder 4 with the slot engaging ends arranged in alignment and with the three. bits thus yplaced as shown in Figure l, and5 the screw 'f7`0 driver will engage successfully with a heavy slotted screw. y

It will be noted that the outerbits 10 as shown in Figures land 5 are arranged'witli Y. their outer slot-engaging ends in alignmentu75 and" that the extreme inner ends thereof engage the top of the-stud l2 to support the bits Ain their extended aligned position.

yThese outer `bits are each provided with a' notch or offset l0 at the inner endfso thatf`80 whenrit is desired to lower either of said side bits, the latter are'removed and turned half a turn so that the ofsetendv formed by the notch 10 will pass the studwhich is slightlyr wider than any of the bits, thus retreatingl85 further into the chuck or holder leaving the remaining bit orbits supported in extended working position. In this way, by manipulating the .outer bits, the effective width of ythe slot-engaging or working end of the`v screw driver may be varied in accordance with requirements from theinaximum three blade width to the medium and minimum two and one blade widths respectively.' n Vhen the tool is to be used with tubularv spoke screws the offset ends may be arranged in the outward position to provide'a slightlyfwider space in the centre, as shown in Figure 3. I

lIt will be noted that as the ends 6'of the-100 holder 4 are chainfered, the placing and removing of the bits in the 'holder willV be rendered very simple.

l have shownthe invention applied to a hand operated screw driver but it Ywill be understood the chuck endcan be provided with a drill holderrhandle or the handle of a brace. Y

That I claim as my invention is:

1. A screw driver, comprising the combination with a chuckhaving a transverse slot i in the end adapted to hold a plurality ot bits, of a plurality of rectangular parallel-sided screw driver bits adapted to be placed side by side in said slot and having transverse slot-engaging ends, therouter bits.. having stepped portions, means carried by` said chuck co-operating with the stepped portions Vot said bits to effect' their relative positioningin the.l slot to be used eithersiii,j2,"lyor collectivelyrin accordance with their position in saidy slot, and Vmeans tor clamping said bits within said slot.

2.*In a screw driver, the combinationwith.

az transversely slotted chuck, otV a plurality of screw driver bits each formed of a length offsquare steel having a tapered end extend- .ing from side'- to side thereof, said bits being adapted tov be arranged side by` side iii the chuck` slot, the outer bits having notched inner ends, means adapted-'to cooperate with the notched inner ends of said bits to support the Vsaine in extended or retracted position in the lslot withl their outertapered ends -in or out of operative alignment, and means forfclamping saidv tools in their adjusted positions in the slot.

Y 3. In. ascrew driver, the combination with-a transversely slotted chuck, of a bit helder,.arranged` inthe chuck slot',y having means at its inner end tofcoopera'te `with the inner ends ofV thebits, a plurality ot'screw driver bits'nested side by side in the chuck slot having outer reduced screw engagingY ends,-the outer'bitshaving their inner ends notched to co-operate with said bit holder means whereby saidbitsniay be supported dental displacement. Y

6. A screw driver, comprising the combination witha transversely slotted chuck, of a plurality oit parallel sided bits adapted to fit into said slot, the outer of said bits having lnotches forming offset' inner ends, a U-` shaped metal bit holder adapted to lit intof said slot and having a squared studA arranged centrally of the bottom thereof, said stud being slightly wider than either ot' said bits and` adapted to support said bitsin an eX- tended position, the oilset ends of the outer bits being adapted to fit betweei'r'the stud and the side walls of the holder leaving the Y inner bit projecting and adapted to be placed in said holderrwith said inner notched ends engaging said stud to support the o uter ends ot said outer bits'inV co-operative alignment with the inner bit,. and meansV for clamping said holder and bits'rigidly together;

PETEE L. i'ioEEEpTsoN:

'thelatter will retain the bits against acciin an extended or retracted position inthe chuck slot in accordance with their. position in the holder, and means torclampingl said bitv holder on said. `bits to`hold the latter rigidly together in their positioned relation. 4. In a-screw driver,fthe combination with atransversely slotted chuck, ot a plurality adapted to bearranged side by side in the l of screw driverbits. each `formed of. a length of square steel havinga tapered end extending, tromside to side thereof, saidbits being chuck slot, the outer bits having. notched inner ends,-aY U-shapedholder member fitting in the-chuck slot and embracing said bits thereinpsaid U-shaped holder having-a raised portion adapted to'A co-operate with the notched inner ends of said outer bits to sup- `pgort the latter 'in their extended or retracted 

